Recently, for improved functionality in a portable terminal device that performs remote communications with others, those provided with a means built into a body thereof, for communicating with external devices by way of RFID (Radio Frequency Identification), which is a contactless IC (Integrated Circuit) chip, and the like, are becoming common (see Patent Documents 1 and 2).    Patent Document 1: Japanese Unexamined Patent Application, First Publication No. 2004-62665    Patent Document 2: Japanese Unexamined Patent Application, First Publication No. 2005-339578    Patent Document 3: Japanese Unexamined Patent Application, First Publication No. 2001-344574